Chronic infections with hepatitis B or hepatitis C viruses are global health problems affecting hundreds of millions of people worldwide. Various commercial products of interferon alpha are approved in the United States for the treatment of adults with hepatitis B and hepatitis C. However, therapy with interferon involves multiple weekly injections via intramuscular or subcutaneous routes, which can be inconvenient, sometimes painful, and often anxiety producing. Because of its widespread and long-term use by the patients with chronic hepatitis B and hepatitis C, and because it is predominantly delivered by parenteral routes, interferon alpha is considered as one of the leading therapeutic protein candidates for delivery via alternative routes. With the approval of the first inhaled insulin product by the US FDA, pulmonary route has proved to be a viable alternative to injection in the treatment of acute human diseases. Thus, the development of an effective and convenient pulmonary administration methods for interferon alpha would be a significant improvement for the lives of patients who are currently receiving interferon therapy by injection. In this Phase I, we describe a method to develop interferon alpha formulations for pulmonary administration using our biodegradable and non-toxic calcium phosphate (CaP) particle technology. The design of the delivery system incorporates our knowledge, understanding, and previous experience in formulating protein drugs for pulmonary administration. The proposed formulation consists of IFN-incorporated CaP particles, which are manufactured in the presence of polyethylene glycol. The Phase I of the project includes formulation, physicochemical and biophysical characterization of the proposed IFN delivery system to assist us in formula optimization and process development. The biological viability of IFN, post formulation, will be judged, by evaluating its potential to activate IFN-induced cellular pathways in HepG2 cell cultures, and its anti-viral activity in a HCV replicon sytem. The potential of CaP-IFN particles to deliver IFN across the lungs into systemic circulation will be evaluated in normal rats using intratracheal administration approach. The clearance of CaP particles from the lungs following the intratracheal administration will be evaluated using fluorescence labeling and microscopic imaging techniques. The aims of Phase I are designed to guide us to identify the critical parameters of the proposed pulmonary delivery system for IFN for further investigation in Phase II. [unreadable] [unreadable] Public Health Relevance: In the current Phase I, feasibility of developing an interferon alpha formulation for pulmonary administration using BioSante's proprietary calcium phosphate (CaP) particle technology will be investigated. The proposed formulation for preliminary investigation will be developed by co-precipitation if IFN alpha with CaP particles in the presence of polyethylene glycol (PEG-3350). The components of CaP-PEG-IFN delivery system are all listed as `Generally Regarded as Safe', or GRAS, by the US FDA. Phase I of the project includes formulation and physicochemical characterization of the proposed IFN delivery system to assist us in formula optimization and process development. The retention of biological activity of IFN in the formulation will be evaluated in-vitro using a human hepatoma HepG2 cell line and by screening for the IFN-induced activation of 2',5' OAS genes by a R/T PCR method. The potential of CaP-IFN particles to deliver IFN across the lungs into the blood stream will be evaluated in normal rats using intratracheal administration approach. The clearance of CaP-IFN particles from the lungs following the intratracheal administration will be evaluated using fluorescence labeling and fluorescents imaging techniques. A decision whether to proceed into Phase II or not will be made based on the critical review of the findings by the members of the project team and based on consultations with NIH and other colleagues in the field. [unreadable] [unreadable] [unreadable]